| Ultrasonic motor(USM)is a prominent representative of precision drive components and widely applied in various fields with different working environments.The actual experimental environment is the atmosphere,while the working environments in the aerospace and other fields is a vacuum.In order to get a more accurate working status of the ultrasonic motor,it is essential to study the influence of the gas under its working condition.Based on Φ60 traveling wave type rotary ultrasonic motor(TRUM),this paper developed the gas film model generated during the operation of the motor and conducted the numerical simulation of gas film by using Computational Fluid Dynamics(CFD)software FLUENT and the moving grid technology.In addition,the characteristics of gas on the motor have been studied,which has a critical theoretical meaning.In this thesis,the main contributions were summarized as followed:Firstly,the working principle and contact mechanism of TRUM is briefly introduced.The gas film theory is analyzed and discussed.Secondly,the model establishment of the gas film and the moving grid technology is studied.The reliability of this model is verified by comparing with the previous models.The model is used to analyze the results of the gas film model considering the contact in the ultrasonic motor under various conditions,including velocity distribution and pressure distribution with and without tooth model.Parameters study has been conducted to estimate the effect of stator amplitude,stator / rotor contact area and contact surface roughness of the film.Thirdly,the influence of the gas film on TRUM is analyzed.The rotating speed and the contact stress drops,which verify that there is a degree of impact on motor considering gas film. |
PDF Full Text Request